mysql merge 分区

原文链接：https://www.bestqliang.com/#/article/5

1.测试数据

1.usera 插入500w数据
2.userb 插入500w数据
3.userall (主表)
    usert1 (子表) 插入250w数据
    usert2 (子表) 插入250w数据
4.userall2 (主表)
    usert3 (子表) 插入250w数据
    usert4 (子表) 插入250w数据

• 建表语句

CREATE TABLE usertb(
    id serial,
    uname  varchar(20) ,
    ucreatetime  datetime  ,
    age int(11))
ENGINE=MYISAM
DEFAULT CHARACTER SET=utf8 COLLATE=utf8_general_ci
AUTO_INCREMENT=1
ROW_FORMAT=COMPACT;

CREATE TABLE usertall(
    id serial,
    uname  varchar(20) ,
    ucreatetime  datetime  ,
    age int(11))
ENGINE=MERGE union(usert1,usert2) insert_method=last
DEFAULT CHARACTER SET=utf8 COLLATE=utf8_general_ci
AUTO_INCREMENT=1
ROW_FORMAT=COMPACT;

• 使用存储过程插入测试数据

delimiter $$
SET AUTOCOMMIT = 0$$
create  procedure test1()
begin
declare v_cnt decimal (10)  default 0 ;
dd:loop
        insert into userta values
        (null,'用户1',now(),20),
        (null,'用户2',now(),20),
        (null,'用户3',now(),20),
        (null,'用户4',now(),20),
        (null,'用户5',now(),20),
        (null,'用户6',now(),20),
        (null,'用户7',now(),20),
        (null,'用户8',now(),20),
        (null,'用户9',now(),20),
        (null,'用户0',now(),20);
        commit;
        set v_cnt = v_cnt+10 ;
            if  v_cnt = 5000000 then leave dd;
            end if;
        end loop dd ;
end;$$
delimiter;

• 调用存储过程

call test1;

• 测试查询时间

select * from userta;       --3.63s

注意点

1.分表必须保证主表和子表表结构一致，否则报错
Error Code : 1168 Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist